In the art of fire protection also so-called spray coatings are known, which can be directly applied to a building construction in order to provide an adequate fire protection. E.g. European patent application 1 001 000 discloses such a spray coating and application method thereof. This known method comprises the steps of preparing a slurry capable of originating a refractory material upon firing, and coating a layer of the unfired slurry onto the construction to be protected. The basic idea of this known method is that the thermal energy in case of a fire is used to build up an effective fire protection. In the specification it is said that the slurry as such can be obtained by adding water to a known mixture, which mixture is used in the manufacturing industry of refractory materials to shape panels and bricks, that are then fired to manufacture the desired refractory articles. This spray coating method and composition have proven their value in fire protection of civil engineering constructions, for example in submarine tunnels.
A preferred composition according to this patent application comprises kaolin, chalk, powdered isolating refractory brick, refractory filler, sawdust, aluminous cement and possibly portland cement. A cementiceous composition according to the above European patent application is available as FireBarrier 135 from Thermal Ceramics.
However, it would be very useful to use this composition in the preparation of casted building articles, such as flat panels, blocks and bricks, which exhibit the same fire protection properties as the spray coating. Unfortunately it has been shown that the processing time of the ready-to-use mixture for casting such articles is insufficient (in the order of 10 minutes), resulting in premature curing and inadequate quality of the articles thus casted.